#define _CRT_SECURE_NO_WARNINGS 1
#include<iostream>

using namespace std;

int main()
{
    string src;
    int len = 0;
    getline(cin, src);

    for (char c : src)
    {
        if (c >= '0' && c <= '9')
            len++;
    }
    cout << len << endl;
    return 0;
}